Known in the present state of the art is a composition humic-silicon sorbent comprising a mineral matrix and humic acids chemically bonded thereto (RU Pat. No 2108895 A).
However usability of said known sorbent is limited to only binding of ions of heavy metals. It is due to the fact that the sorbent producing processes are multi-stage ones comprising the steps of extracting, neutralizing, filtering, washing, drying, and calcining that the resultant sorbent has high cost, whereby its use is impracticable.
One more humic concentrate is known to comprise artificially (technically) hydrated humic acids, salts thereof, and mineral components chemically bound to humic acids (RU Patent No 2125039).
Said known humic concentrate is characterized but a low active principle concentration (not more that 15%) which is accounted for by an electrolysis method of its preparation and by its composition little or amenable to be controlled or practically uncontrolled which is predetermined by a complex and heterogeneous electrolyte composition and too complicated control of the electrolysis process. The humic concentrate appearing as a gel (having a minimum moisture content of 85%) features high stickiness, whereby it is extremely inconvenient to handle. In addition, said known concentrate has a relatively high cost due to complicated and power-consuming production processes thereof comprising crushing and disintegrating the original feedstock, i.e., humites and caustobioliths of carbon series, extracting, separation of a solid and liquid phases, and electrolysis of an alkaline solution which predefines a limited practical use of said concentrate.
Another method for producing humic preparations is known to comprise simultaneous coal crushing and mixing it with an alkaline solution, and separation of an extract after heating (RU Patent No 2130004 A).
Said known method is characterized by a great amount of waste products, since an aqueous extraction is in fact the end product, while treated coal is a waste product; restricted use of the resultant aqueous extract only as a biologically active preparation in farming practice; high consumption rate of an alkali or ash resulting from coal or wood burning. In the latter case the ash content is practically uncontrollable which affects adversely the composition and properties of the end product obtained.
Still one more method for producing humic fertilizers is known to comprise ultrafine disintegration of coals containing humic acids in a mixture with hydroxides of alkali metals, the starting mixture being preliminarily dried to a (RU Patent No 2104988 A).
However, a necessity for preliminary drying of said mixture of coal and hydroxides of alkali metals to a final moisture content of from 6 to 12 wt %, as well as a necessity for a ultrafine disintegration of the starting mixture result in high power consumption rate and low efficiency of the process. Besides, in the course of coal drying the humic acids and their derivatives contained in the coal are dehydrated, with the result said derivatives are rendered in a dormant state.
A subsequent alkaline hydrolysis of such substances involves use of a great amount of alkaline agents, in particular, hydroxides of alkali metals which make up 20 to 35% of the coal weight. The end product obtained contains a great proportion of alkali and has a high pH value which restricts its use only as a carrier or source of ammonium humates and/or humates of alkali metals, the spread of use of which as well as demand therefor are extremely low and are limited to the sphere of regulators (biostimulators) of growth and development of plants.
Of great importance is the fact that it is due to absence of requirements to starting coal, wherein depending on the genesis, conditions of occurrence in a seam and preceding geological history that the content of organic toxicants, such as benzpyrene, and of inorganic toxicants, e.g., ions of heavy metals, i.e., beryllium, arsenic, mercury, lead, may reach dangerous concentrations. The end product comprises virtually the same concentrations of the aforementioned toxicants and therefore becomes harmful for practical use.
Levels of soil contamination with inorganic (heavy metals) and organic (hydrocarbons of oil and of products thereof, polychlorinated and polycyclic compounds) ecotoxicants reach in some instances dangerous values, whereby the problems of sanitation (detoxication) of contaminated soils and territories.
A method for soil vermireclamation and decontamination from oil and products thereof (RU Patent No 2119735, IPC A01B 79/02, published Oct. 10, 1998, Bulletin No 28), comprising applying a vermicompost to contaminates soils.
However the known method suffers from high cost for vermicompost preparation and is of low efficiency for detoxication and decontamination of soils polluted with both oil products and heavy metals.
It is also known a method for reclaiming agricultural soils and land detoxication, including applying to said soil a humic substance in the form of water-soluble humic acids (RU Patent No 2031095 A).
However, detoxication of polluted soils according to said method is of low efficiency due to rapid washing of water-soluble humic acids our of soil and their decomposing under the effect of physical-and-chemical factors (too low or high pH values of polluted soils) and of microbiological ones. In addition, it is due to a high cost of water-soluble humic acids a complicated production process thereof that the method in question has found no practical use whatever.
A great amount of waste products results from routine work of industrial enterprises which when stocked in stockpiles, dump pits, slurry and tailing dumps are a dangerous source of pollution of the surrounding natural environment with toxic chemical elements and compounds making part of said waste products and resulting from processes of their storage.
A land reclamation method is known to comprise putting in dumps potentially fertile kinds of loess, clay and sand, followed by applying a humus-incorporated coat thereto (SU Patent No 605958).
The known method is characterized by high labor input and material consumption rate and fails to provide an efficient dump and pile detoxication.
A method for detoxication of waste materials of winning and processing useful minerals and reclaiming waste pile and tailing pits is known to comprise applying a detoxifier agent (e.g., lime) and mixing it with waste materials, and depositing a soil layer (cf. a textbook “Environmental protection during operation of tailing pits”, by P. V. Beresnevich, P. K. Kuzmenko, and N. G. Nezhentseva, Moscow Nedra Publishers, 1933, pp. 102–107).
The known method is characterized by high consumption rate of detoxifier substances, high labor input, and lower efficiency.
One of the most dangerous sources of environmental pollution is sewage water of industrial, agricultural, and other productions.
A method for sewage water treatment from inorganic, organic, and microbiological impurities is known to comprise adding to water bactericidal and other agents, water sedimentation, and sediment withdrawal (cf. a textbook “Sewage water treatment and decontamination at small settlements”, Leningrad, Stroiizdat, 1993, pp. 113, 121, 124 (in Russian).
Used as said agents are mineral coagulants (aluminum sulfate, ferric chloride, and others), organic flocculants (polyacrylamide and derivatives based thereon), as well as a variety of combinations of said coagulants and flocculants.
The method in question is characterized by a relatively high cost and toxicity of the agents used, formation of a great amount of sediments hardly amenable to dewatering, and dependence of the water treatment process efficiency on composition and concentration of pollutants and water temperature.
A method for sewage water treatment is known to comprise adding to water an agent in the form of a humic concentrate, water sedimentation, and sediment withdrawal (RU Patent No 2125039 A).
The method, however, failed to find practical use due to a complicated process for humic concentrate production and a high cost the agent itself.
Surrounding natural environment is badly polluted also with sewage sediments, including municipal sewage sediments (MSS) which comprise a great proportion of organic waste and biogenic elements (nitrogen, phosphorus) and thus are good fertilizers, On the other side, MSS contain a great amount of ions of heavy metals, hydrocarbons of oil and oil products, as well as polycyclic and polychlorinated organic compounds.
The problem of detoxication and ecologically safe salvaging of MSS is a very urgent one for many scores of years.
A method for salvaging sewage sediment is known to comprise its mixing with peat and mineral components and applying said mixture to the soil as an organoinorganic fertilizer (SU Patent No 836005).
However, ions of heavy metals contained in MSS are not bound but are free migrate into the environment, thus contaminating ground water and intoxicating crop production. Besides, use of MSS is possible only on a restricted amount and periodically, that is, once per several years, with the proviso that its use performed is under a continuous ecological monitoring and sanitary-epidemiological control.
One more method for sewage sediment salvaging is known to comprise adding a humic preparation thereto (RU Patent No 2125039, A).
However, said method sails to find widespread use due to a complicated production process and high cost thereof.